In recent years, the environments of communication networks such as LANs that perform high-speed high-capacity data transmissions have not been limited to offices inside buildings, and the use of high-speed high-capacity data transmissions using communication cables such as Ethernet® cables has spread to harsh environments subjected to external influences, inside passenger aircraft, and to industrial fields such as inside factories, or inside railway cars.
Communication cables that are connected between communication devices have a structure wherein braiding is provided under a skin known as a sheath or jacket, and these cover paired wires (two sets of two or two sets of four) forming signal lines. The braiding has a shielding function of blocking external electromagnetic waves and a grounding function of connecting the ground lines between communication devices.
Regarding the grounding function of the braids, a certain grounding format may be required in the connectors when connecting certain devices via a communication cable with connectors attached at both ends thereof.
As the certain grounding format in the connectors, it is possible to conceive of two grounding formats, i.e. a grounding format wherein the braiding of the communication cable is connected to a ground line in a printed circuit board (hereinafter abbreviated to PCB) inside the communication device (hereinafter referred to as PCB grounding), and a grounding format wherein the braiding of the communication cable is connected to the external frame body of the connector which is in turn connected to a frame provided on a metallic box or the like housing the communication device (hereinafter referred to as frame grounding).
PCB grounding refers to a grounding format wherein the braiding of the communication cable is grounded by connection to the ground line of a PCB in the communication device, and frame grounding refers to a grounding format wherein the braiding of the communication cable is connected to the external frame body of a connector having the purpose of providing a shielding effect to block external noise, the external framework being in turn connected to a frame for grounding such as a metallic box housing the communication device or the like.
Additionally, when attaching a communication cable to a communication device via a connector in a harsh environment or in an industrial field, under the conventional art, for example, round connectors were used, one of which was installed on each of a plurality of cables, and the connectors were each coupled manually into a corresponding group of receptacle connectors mounted on a panel of the communication device.